I am in need of help, I purchased an MTH locomotive with no sound but the box say accepts proto 1 plug in sound. I have a lot of extra Proto 1 sound boards with sound chip, is this the only thing I need to upgrade the loco to sound? I don’t want to open it up and screw anything up by plugging it in wrong. MTH has no info on it and I have had no success at reaching a tech at MTH.
Kevin